Moving, carrying, and feeding your baby challenges your body in new ways. New moms are also more prone to injury until relaxin, the hormone that makes muscles more elastic before birth, leaves the body (usually a few months postpartum), says physical therapist Gail Pekelis, owner of Women's Physical Therapy Rehabilitation in Los Angeles. The following tips can help you stay pain-free: Nursing: You'll be more comfortable if you sit in a chair with a back that's high enough to support your head and that allows your knees to be slightly higher than your hips, says Pekelis. Place soft pillows behind your back and under your arms for support. As tempting as it is to gaze down at your baby, keeping your head back will help you avoid neck strain. Lifting: When picking up your baby, use your legs, not your back. Stand as close to the crib or changing table as you can, bending your knees slightly. Reach one hand under your baby's bottom and the other under her neck. Then use your legs to lift. Holding: "Aim to keep your shoulders dropped and your neck relaxed to avoid muscle strain," Pekelis says. If possible, avoid perching the baby on your hip; keep her weight balanced between your sides instead.